WASHINGTON -- Wade Miley gave Arizona a chance by repeatedly working out of trouble. Third baseman Jordan Pacheco threw it all away in the ninth.
Pacheco's throwing error allowed Denard Span to score the winning run in Washington's 1-0 victory over the Diamondbacks on Thursday.
"I guess some losses are a little more difficult," first baseman Mark Trumbo said. "I think we battled as well as we could. Just didn't have too much offense to show for it. But our pitching staff did a great job."
Arizona dropped the last six games of a 2-8 road trip. Eight of the Diamondbacks' last 10 games have been decided by one run. Arizona lost six of those one-run games.
Rafael Soriano (4-1) pitched a scoreless ninth as Washington stretched its winning streak to 10, matching the franchise record. Five of Washington's last six wins have come in its final at-bat of the game.
"I feel like it was bases loaded, one out every inning. Just trying to make pitches, and I was fortunate enough to get a couple ground balls."
Miley retired Adam LaRoche three times to end an inning -- twice on double plays -- before walking him to load the bases with two out in the seventh. Matt Stites got Wilson Ramos to fly out to right to end the threat.
The Nationals went 0-for-13 with runners in scoring position.
Arizona's best chance came in the third, when Miley's sacrifice put runners on second and third with one out, but Ender Inciarte lined to shortstop and Cliff Pennington flied out.
Pennington also popped out with the bases loaded and two outs in the fifth.
Gio Gonzalez pitched seven innings for Washington. He allowed four hits and walked three while lowering his career ERA against Arizona to 1.33 in three starts.
Nationals: INF/OF Ryan Zimmerman (right hamstring strain) threw on the field for the first time since going on the disabled list July 23. There is no specific timetable for his return. "You have to use that muscle to throw," Williams said. "It's part of the strengthening process." ... OF Nate McLouth was scheduled to have season-ending shoulder surgery Thursday, Williams said.
Diamondbacks: INF Chris Owings (left shoulder strain) will continue his rehab assignment at Triple-A Reno on Friday after going 4-for-7 in three games with Arizona's rookie league club. ... OF A.J. Pollock (fractured right hand) took light batting practice Thursday.
Diamondbacks: RHP Josh Collmenter (8-7, 4.31 ERA) will make his fifth career start against San Diego on Friday as Arizona begins an eight-game, 10-day homestand.
Trumbo became just the second Diamondbacks runner in 12 attempts to be caught stealing when Ramos threw him out at second to end the sixth.